Here is a collection of sites where you can get PC game mods!
https://steamcommunity.com/workshop/ If you have a game on steam, you can use the workshop to find mods for many of them - however I strongly encourage backing up any mods you like as they can dissapear from the workshop!
http://steamworkshop.download A handy site that can extract steam workshop mods for you to directly download!
https://gamebanana.com/ Once called FPS banana, they now host mods for many kinds of games - first person shooters, rhythm games, platformers, and more!
https://www.nexusmods.com/ A fancy mod site that covers many games such as Skyrim, Fallout, etc.
https://www.moddb.com/ Another classic mod site with lots of nice stuff on it!
https://www.gamemaps.com/ A site specializing in hosting custom maps for PC games!
https://www.gamepressure.com/download/ A game news site that also hosts a collection of PC game mods!
https://archive.org/ A great site that archives many things, including old video game mods and maps!
https://www.curseforge.com/ A nice site that hosts maps and mods for many games, including Minecraft, The Sims, Stardew Valley, and more!
https://www.gamefront.com/ Originally known as Filefront back in the day, GameFront is still around and has a big collection of maps & mods for games like Quake, Half-Life 2 and more!
